Thomas Simmons was born on August 12th 1995 to Marvin and Anja Simmons. He has a twin brother, Christian, who is 26 minutes older than him. He got his bachelors degree in engineering when he was 20 and started to work at A.S. Industries right after that. It was there where he met Fujiko Suzusaki and the two got married on June 1st 2016.

On July 18th 2017 Thomas was working on a project at home when an explosion ruputred the entire complex. he was engulfed in flames and the fire burned him to a crisp. However he did not die. Instead he awoke two months later on September 21st 2017 in the rubble of what once was the A.S. Industries complex. Having flashes of his previous life and his wedding he soon met Shin and Nightstar , two vigilantes fighting a huge monster. Seeing the urgency of the fight he decided to join in just to realize that he suddely has tremendous strength. He helped them defeat the monster and together they escaped into the sewers.

After fixing Nightstar's arm, he realized how long he was out cold and remembered that he had a wife, FUjiko, who was now dead and Alvin Severnya was to blame. He had a nervous breakdown and ran off, with Shin and Nightstar running after him. When they caught up to him, the pain he felt ever since is awakening worsened and the Bio-Suit broke through his skin, transforming him into Nightfighter. The Suit, now permanently bonded with him came handy immediately as they were attacked by Cyborgs Chrome and Glacia, both sent by Severnya to retrieve the Bio-Suit. A fight ensued and while the heores held their own, the cyborgs proved to be too much and defeated them by freezing them in solid ice. They took Nightifghter and brought him to Severnya, leaving the others for dead.

Shin and Nightstar did survive, though, and Nightfigther woke up to Severnya's voice. Severnya teased him with admitting to killing his wife and then tranformed into the beast the heroes faced in the warehouse. Nightfigther and the beast fought, as Severnya wanted the suit and Nightfigther wanted revenge for the death of his wife. Thomas managed to slit Severnya's throat and the entire building fell apart, taking them both down.

Thomas however survived all of that and was rescued by Nightstar and Shin. A little bit later he went to the grave of his wife, apologizing for not being able to save her and telling her that he will use his newfound powr for good.

Thomas is very righteous and courageous. He is an engineer and a smoker, although he quit smoking after he became Nightfighter, partly because he wanted to and partly because he had no choice, since the suit as fused with him. He is smart and a little bit hot headed, a romantic at heart and quick to adapt to new situations.